fix: correct hooks.json structure per Claude Code documentation

Three plugins had incorrect hooks.json structure that caused hooks to fail:

- pr-review: SessionStart used nested `hooks` array without matcher
- cmdb-assistant: SessionStart used nested `hooks` array without matcher
- git-flow: Used completely wrong format (array with `event` field)

Per Claude Code documentation:
- Without matcher: direct `type`/`command` in the event array
- With matcher: nested `hooks` array inside matcher object

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

plugins/cmdb-assistant/hooks/hooks.json

@@ -2,12 +2,8 @@
   "hooks": {
     "SessionStart": [
       {
-        "hooks": [
-          {
-            "type": "command",
-            "command": "${CLAUDE_PLUGIN_ROOT}/hooks/startup-check.sh"
-          }
-        ]
+        "type": "command",
+        "command": "${CLAUDE_PLUGIN_ROOT}/hooks/startup-check.sh"
       }
     ],
     "PreToolUse": [

plugins/git-flow/hooks/hooks.json

@@ -1,16 +1,19 @@
 {
-  "hooks": [
-    {
-      "event": "PreToolUse",
-      "matcher": "Bash",
-      "type": "command",
-      "command": "${CLAUDE_PLUGIN_ROOT}/hooks/branch-check.sh"
-    },
-    {
-      "event": "PreToolUse",
-      "matcher": "Bash",
-      "type": "command",
-      "command": "${CLAUDE_PLUGIN_ROOT}/hooks/commit-msg-check.sh"
-    }
-  ]
+  "hooks": {
+    "PreToolUse": [
+      {
+        "matcher": "Bash",
+        "hooks": [
+          {
+            "type": "command",
+            "command": "${CLAUDE_PLUGIN_ROOT}/hooks/branch-check.sh"
+          },
+          {
+            "type": "command",
+            "command": "${CLAUDE_PLUGIN_ROOT}/hooks/commit-msg-check.sh"
+          }
+        ]
+      }
+    ]
+  }
 }

plugins/pr-review/hooks/hooks.json

@@ -2,12 +2,8 @@
   "hooks": {
     "SessionStart": [
       {
-        "hooks": [
-          {
-            "type": "command",
-            "command": "${CLAUDE_PLUGIN_ROOT}/hooks/startup-check.sh"
-          }
-        ]
+        "type": "command",
+        "command": "${CLAUDE_PLUGIN_ROOT}/hooks/startup-check.sh"
       }
     ]
   }